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-rw-r--r--librt/shm.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/librt/shm.c b/librt/shm.c
new file mode 100644
index 000000000..c7c0ee461
--- /dev/null
+++ b/librt/shm.c
@@ -0,0 +1,101 @@
+/* Copyright (C) 2009 Bernhard Reutner-Fischer <uclibc@uclibc.org>
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */
+
+#include <features.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+#ifndef _PATH_SHM
+#define _PATH_SHM "/dev/shm/"
+#endif
+
+#ifndef NAME_MAX
+#define NAME_MAX 255
+#endif
+
+/* Get name of dummy shm operation handle.
+ * Returns a malloc'ed buffer containing the OS specific path
+ * to the shm filename or NULL upon failure.
+ */
+static __attribute_noinline__ char* get_shm_name(const char*name) __nonnull((1));
+static char* get_shm_name(const char*name)
+{
+ char *path;
+ int i;
+
+ /* Skip leading slashes */
+ while (*name == '/')
+ ++name;
+#ifdef __USE_GNU
+ i = asprintf(&path, _PATH_SHM "%s", name);
+ if (i < 0)
+ return NULL;
+#else
+ path = malloc(NAME_MAX);
+ if (path == NULL)
+ return NULL;
+ i = snprintf(path, NAME_MAX, _PATH_SHM "%s", name);
+ if (i < 0) {
+ free(path);
+ return NULL;
+ } else if (i >= NAME_MAX) {
+ free(path);
+ __set_errno(ENAMETOOLONG);
+ return NULL;
+ }
+#endif
+ return path;
+}
+
+int shm_open(const char *name, int oflag, mode_t mode)
+{
+ int fd, old_errno;
+ char *shm_name = get_shm_name(name);
+
+ /* Stripped multiple '/' from start; may have set errno properly */
+ if (shm_name == NULL)
+ return -1;
+ /* The FD_CLOEXEC file descriptor flag associated with the new
+ * file descriptor is set. */
+#ifdef O_CLOEXEC
+ /* Just open it with CLOEXEC set, for brevity */
+ fd = open(shm_name, oflag | O_CLOEXEC, mode);
+#else
+ fd = open(shm_name, oflag, mode);
+ if (fd >= 0) {
+ int fdflags = fcntl(fd, F_GETFD, 0);
+ if (fdflags >= 0)
+ fdflags = fcntl(fd, F_SETFD, fdflags | FD_CLOEXEC);
+ if (fdflags < 0) {
+ close(fd);
+ fd = -1;
+ }
+ }
+#endif
+ old_errno = errno;
+ free(shm_name);
+ errno = old_errno;
+ return fd;
+}
+
+int shm_unlink(const char *name)
+{
+ char *shm_name = get_shm_name(name);
+ int ret, old_errno;
+
+ /* Stripped multiple '/' from start; may have set errno properly */
+ if (shm_name == NULL)
+ return -1;
+ ret = unlink(shm_name);
+ old_errno = errno;
+ free(shm_name);
+ errno = old_errno;
+ return ret;
+}